
Did Pluto form like its closer-in brethren in the solar system, or is it the result of an agglomeration of comets from the edge of the solar system? A study published in the journal Icarus makes the case for comets.
To reach that conclusion, Christopher Glein and J. Hunter Waite Jr. of the Southwest Research Institute compared chemical analyses from NASA’s New Horizons mission to Pluto with readings from the European Space Agency’s Rosetta mission to Comet 67P/Churyumov-Gerasimenko.
The result is what’s known as the “giant comet” cosmochemical model of Pluto formation.